Justin-justin_le wrote:Oddly that was the original plan in the first CA rather than showing the trip aggregate, but I found in practice it is less useful than I would have thought. Your instantaneous Wh/km moves around an order of magnitude between going up steep hills and accelerating vs. riding on the flat with a tail wind, and so seeing you briefly pull 100 Wh/km doesn't necessarily mean much (in terms of what your total usage will be) if it's getting you up to speed or up in elevation. ... you'd probably want it to be a longer time averaged version of the mileage. ... I think for user feedback something that is more like a 20-30 second rolling average of the mileage figure would be more meaningful that instant, which is pretty jumpy. ... Another possibility would be to have a stats reset counter that will refresh the Wh/km figure but not say your total distance or total Ah.teklektik wrote:Justin-
One thing that my auto ECU offers for display that is absent on the CA is Instantaneous Mileage. In CA terms this would be Instantaneous Wh/mi.
Thanks for the quick response. I agree 100% with your assessments of the problems with an instantaneous value. I find the same issues with Instantaneous MPG in my auto and address them in a manner similar to what you have proposed - resetting the Avg MPG for a test run or repeatedly as a poor man's rolling average.
I really wanted to fly the basic idea and leave the details up to you since the biggest part of the problem is not the calculation but resource management - display area, top level button pushes, memory for rolling calculations, additional configuration, etc. Some of the solution could be tied to the configurable screen concept discussed in earlier posts, etc, so diving into supporting details seemed like it might muddy the concept presentation.
That said, a rolling mean with a configurable max period (sample lifetime) of 15-30 seconds would be terrific even if the granularity of the rolling sample period was only something like 5 seconds. Different levels of reset are somewhat attractive, but I don't believe the feature value warrants complicating the button press situation (particularly those that need to be accomplished while underway).
Since these are in the same general category of energy expenditure metrics, this could be a nice approach.justin_le wrote:Thinking about how to implement it. Right now you can choose between watts or amps on the main screen, and there could easily be a 3rd choice to show Wh/km instead.
This seems less attractive, but still workable. In this case, you might forego the rolling average in lieu of a running average that resets when the Wh/mi display value goes out of sight. It would then begin accumulating the new value and continue to average in new values until reset again in the next rotating display cycle. The advantage would be eliminating the configuration of a rolling period (driven instead by display period), and eliminating storage needed to maintain a rolling value (there would only be the current accumulated average since last reset). This seems slightly sub-optimal but still valuable as a compromise while we're saving resources for other goodies...justin_le wrote:Other possibility would be to have it toggle with the Ah and Distance (and optional Temp) data. In that case though, you'd probably want it to be a longer time averaged version of the mileage.
Anyhow - glad to have this on your memo list for consideration...